Cathode-ray tube amusement device



Dec. 14,1948.. I T. 'r. GOLDSMITH, JR., ETAL 2,455,992

CATHODE-RAY TUBE AMUSEMENT DEVICE .Filea Jan. 25, 1947 2 Sheets-Sheet 1' INVENTORS I 'IBY" Dec. 14, 1948- 'T. T. GOLDSMITH, JR., ETAL 2,455,992

CATHODE-RAY TUBE AMUSEMENT DEVICE Filed. Jan. 25, 1947 2 Sheets-Sheet 2 ,J a n h, E Ego n a l 5.466.127 M; 'uvmvrons Patented Dec. 14, 1948 umrao ""srrAr s PATENT ,o -"mcsf Thomas T. Goldsmith, J r., Cedar Grove, and Estle Ra'y Man'n, Upper Montclair, N. J., assignors to Allen: B. Du Mont Laboratories, Inc., Passaic, I N. J., a corporation of Delaware I {application January '25, 1947, Serial No. 724,444

*6 Claims. (Cl. 315-26) 1 --This invention relates'to adevice with whicha game can be played. The-gameis of such acharacter that it requires care and skill in playing it or operating the device with which the game is played. Skill-can be-increased with practice and the exercise of care contributes tosuccess.

In ==carrying out the invention a cathode-ray tubeis used upon the face of which the trace of the ray or electron beam can be seen. One or more targets, such as pictures of airplanes, for example, are placed upon the-face of the tubeand controls are availabletothe player so that he can manipulate the trace or position of the beam which is automatically causedto-move across the face *ofthej tube. This movement of'the beam may be periodic and its repetition rate may be varied. It's path is "preferably caused todepart irom a straight line so as to require an'increased amount of skill and care for success in playingthe game.

The "game can be made more spectacular, and the interest therein both from the players and the observers standpoint can be'increased, by making a visible explosion of the cath o'de ray beam take place when the target is hit.

The invention maybe" understood from the description in connection with the accompanying drawings, in which: 1

Fig. 1 is a diagram of electrical connections suitablefor operatingthedevice; Fig. 2 is-a'di'agram on anenlarged scale, showing some of the details bfFigJl and additional elements; I

*Fig. 3 is a diagram showing "someof the details of a pair of deflecting plates; and

Fig. 4 shows the end of a cathode-ray tube, and suitable controls for' operating thedevice. I

In thedrawings, reference-character 1 indicates a variable resistorthatis in series "with afixed resistor 2. These resistors are fed from any convenient source of positive potential. They are the load resistors of the thyratron '3 which has 'a variable resistor l its-cathode-circuit. A switch 5 is-provided for short-'circuitingthe resistor t, thus firing the thyratronmanually'whenever de-'- sired for a purpose toflce explained later. The grid 6 of the thyratron 3 in connected to ground. The -condenser"l together with variable resistor I and fixed resistor 2 gives the desired time constants for the sawtooth wave which is the output on lead '8 that is connected to the plateof the thyratron 3. Resistor =9 in series-with thevariable resistor- 4 *is used :for setting orfixing' the positive voltage ofthe cathode of thyratronb. I 1 .;..;A nattenuating resistor M ds provided in -the lead 8. This resistor I0 is in series with the re sistors, II and I2 which are in parallel with each other and have one end of each grounded. Resistors I I and I2 are ganged to acommon control M .as indicated by the dotted line so that as one contactor is moved toward ground the other contactor I5 is moved away from ground. The movable contactor IS on resistor I I is connected by lead It to the control grid ll of tube I 8 which is part of a balanced phase inverter deflection amplifier which is to be described below. The plate Id of tube 18 is connected by lead 20 to one of the vertical deflection plates 2| .oi the cathode-ray tube mentioned above and which is indicated at O in Fig. 2. I The load resistor "for tube 18 is resistor 22. The cathode of tube I8 is connected to the cathode of tube 23 which is another tube of the balanced deflection amplifier mentioned above. A resistor .24 connectes the cathodes .of tubes 2H! and 23 toground. Resistor 25 and a variable rer sistor 2.6 are connected in series between a source of positive potential and ground. Lead 23 connectsa point between resistors .25 and 2.6 to the control grid "28 of tube 23. The plate load ofethis tube is resistor 29, and the plate of this-tube is connected by lead 30 to the othervertical deflection plate 3| of the cathode-ray tubeuOfTh-c screen grids of tubes I8 and 23 are connected together by lead .32. This lead is connected by resistor 33 to'the source of positive potentialy-and a capacitor 34 is connected between this resistor 33 and ground.

The amplifier for the horizontal deflection plates of tube 0 is like the one just described, corresponding parts being designated by the same reference characters with primes. However, :the plate load resistors 2 I and 3 I of the two vacuum tubes I9 and 23' difier from resistors 22 and 29. These load resistors 2|" and 3|" :are high'resistance coatings on the two horizontal deflection plates of the cathode-ray tube 0 which will be described later. Lead 35 from contactor I5 extends to thegrid 36 of tube 31. The plate of this tube is connected to a" regulated power supply which may be at 250 v. Lead 38 fromthe contactor 115' 'on resister 12 extends to the grid of :tube '39. The plate of this tube is also connected to :the regulated power supply. The cathode of tube 13] is connected to the cathode of tube 39 lbyLlead .40 which is grounded through resistor 4 I. -A sliding contact 42 onresistor M is connected by lead to the .grid of tube 44. The cathode of tubedd is connected through :resistor 45 to :a source oi positive potential, and this cathode is also grounded through a variable resistor 46. The plate load of the tube 44 is the field coil 48 of a single-pole spring-biased relay. Contactor 49 is spring biased so that as long as this coil is not energized the contactor 49 of this relay is caused to contact with the contactor'50 to focus the beam of the cathode-ray tube 0, as explained more fully below. When the coil 48 is energized by current passing through tube 44 contactor 49;;-

is caused to contact with the contactor i. This defocuses the beam of the tube 0. A positive voltage is applied to the lead 52 that is connected to coil 48. contact 53 (Fig. 2) which slides on resistor 54, and contactor 5| is connected to a sliding contact 55 on resistor 56. The resistors 54 and 56 are connected in parallel. Resistor 51 is connected between one end of the resistors 54, 56 and ground, and resistor 58, which is connected to a source ofnegative potential, is connected between the other ends of these resistors opposite resistor 51. This source of negative potential is connected through lead 59 and resistor 60 to the cathode 6| of the cathode-ray tube 0. A sliding contactor B2 on resistor 53 is coupled by condenser 62' to the lead 59. This sliding contactor (i2 is connected by lead 63 to the control grid 04 of the cathode-ray tube 0. The contactor 49 is connected by lead 65 to the focussing anode 66 of this cathode-ray tube.

' The purpose of contactor 49 and its attendant circuits is to provide the operator with means for de-focussing the beam in the tube 0 at some previously determined position of the spot on the screen, this previously determined position being controlled both by the variable resistor 45 (Fig. l) and the sliding contact 42.

The cathode-ray tube 0 is similar to well known cathode-ray tubes. However, the pair of deflection plates forproducing horizontal deflection of the beam'is diiferent from deflection plates previously used. The vertical deflection plates are the same as those normally used in cathode-ray tubes. Each ofthe horizontal deflection plates 10 consists of a non-conducting base or plate, or support ll (Fig. 3), similar in shape to the present horizontal deflection plates.

High resistance conducting material 2| and 3| such as aquadag, is applied to the inner surface of each of these plates as shown by dotted lines in Fig. 3. The resistance from the lower edge to the upper edge of each conducting layer may, for example, be approximately 30,000 ohms. The cathode-ray tube 0 is assume-d to be mounted with its axis horizontal. The upper ends of these high resistance materials 2| and 3| are in contact with conductors 13 and 14. The lower edges thereof are connected by conductor 75. By lead either through the base or through the glass of the tube 0 positive potential is applied to conductor 75. The outer ends of the conductors l3 and 14 are connected by leads either through the base or through the glass of the tube 0 to plates l9 and 23a (Fig. 1) so that the difference of potential between th two plates 10' (Fig.. 3) is greatest at the edges opposite the conductor 15. The electrostatic field between the two plates increases as the distance from the conductor 15 increases.

As the electrons of the cathode-ray or beam pass between the vertical deflecting plates 2|, 3| (Right hand portion of Fig. 2) described above, the beam is deflected vertically by the sawtooth voltage which is applied to these plates. After Contactor 50 is connected to a sliding 4 this vertical deflection, as these electrons proceed along the tube they pass between the horizontal deflecting plates 10. Since the field between these horizontal plates increases as the distance from the conductor 15 at the lower edge increases, due to the potential drop along the re sistors 2|, 3| (Fig. 3) on these plates, the greater the vertical deflection the greater will be the horizontal deflection.

v The operation is as follows:

The switch 5 is closed, whereupon sawtooth voltage is applied to resistors H and I2.

'Thesawtooth signals are taken ofi by the sliding contactors l5 and I5 and are impressed simultaneously on the grids of tubes 31 and 39. The output of these tubes is taken from the common cathode load resistor 4| by adjustable contactor 42 and lead 43. This output is impressed on the grid of vacuum tube 44 through lead 43.

Vacuum tube 44 is adjusted by variable resistor 46 in its cathode circuit and has a positive potential applied through resistor 45 to its cathode so that this cathode is sufficiently positive to make this tube normally non-conducting. When no current flows through coil 48 the relay 49 (Figs 1 and 2) is spring-pressed into .contact with the contact0r50. This contactor 50 is connected to the sliding contactor 53 (Fig. 2) on resistor 54, which is manually adjusted to the position at which the spot on the cathode-ray tube 0 is sharply focussed due to the fact that the focus electrode 66 is then connected by lead 65 to contactor 50.

When the current through resistor 4|, Fig. l, is suiiiciently high to cause the potential on the grid of tube 44 to start the plate current in this tube, the plate current which varies inasawtooth wave manner passes through the coil 48 and when of sufficient strength brings contactor 49 into contact with contactor 5|, Figs. 1 and 2. The sliding contactor 55 is adjusted on resistor 56 so that it causes the beam on the cathode-ray tube 0 to be considerably out of focus when the contactor 49 is connected to it by contactor 5|, so that instead of there being a sharp spot to trace a pattern on the screen of tube 0, there is alarge round spot which is not nearly as bright as it would be if the beam were asharply focussed image I When a sawtooth voltage on lead 8 (Fig. 1) is impressed in phase upon both balanced phaseinverter deflection amplifiers I8, 23 and I8, 23' as shown in Fig. 1, the trace of the beam on the screenof tube 0 ,is parabolic. If there were no difference of potential from one edge to the other on the deflection plates, then the deflection due to sawtooth voltages would cause a straightline to appear on the screen.- The axis of the parabolic path traced on the screen of the cathode-ray tube 0 as well as the location of this'tracing can be controlled by the. common control l4 (shown by a dotted line in Fig. 1).

The device may be placed in any suitable cabinet with theface of the tube 0 visible through an opening in the front panel thereof. Buttons or knobs for operating the controls may also be mounted on this panel.

In playing a gamewith'this device the player takes a position where'he can see the face of the tube 0, Fig. 4. The end of the beam is at the spot 15 so long as the switch 5 is open. The object is to cause, the beam to be deflected in such a manner that it will strike a selected one of the objects 16 on the face of the tube and become defocussed just as it reaches said object 16, thus simulating destruction or explosion of the object which may be represented as an airplane, for example. The paths 11 of the spot depend upon the potentials applied to the plates 2|, 3|, and 2|, 3! which the player can control by adjusting the contactors I 5 and 15' on resistors II and I2, Fig. 1.

Knobs or buttons 5a, I5a, l5a', lla, 46a, 53a, 55a and 62a. are provided at any convenient place, such as upon the front of a cabinet 80 for the device where the player can reach them and watch the face of the tube (Fig. 4). The knob 5a enables the player to close and open the switch 5 (Fig. 1 at the left) at will. When it is closed a trace 11 appears upon the face of tube 0. The knobs I511 and l5a operate the sliding contacts l5 and I5 (shown in the upper left hand portion of Fig. 1) which control the direction of the trace ll of the beam from the starting point 15 along the face of the tube 0. The controls 4 la and 46a operate the sliding contacts 42 and 46a (bottom left Fig. 1) to control the point at which the cathode-ray beam that produces the traces 11 becomes defocussed or explodes. The controls 53a and 55a operate the sliding contacts 53 and 55 (shown at the upper left hand portion of Fig. 2) which regulate the focussing and defocussing of the cathode-ray beam, and control 62a controls the contactor 62 which adjusts the negative potential that is applied to grid 64', thus controlling the brilliance of the trace.

The object of the game is for the player to adjust the control-s within a specified predetermined interval of time so that one of the parabolic traces ll of the beam will start from the gunners position 15 and hit a selected target or airplane I6 and explode on the selected target.

What is claimed is:

1. In a device of the character described, an electrical circuit comprising a. cathode-ray tube, adjustable means including a sawtooth wave voltage generator, a pair of adjustable resistors between the output of said generator and ground to cause the beam of said tube to sweep from 'a fixed point along different paths along the face of said tube and means to cause said beam to become defocussed at different positions of its sweep by the output from said voltage generator.

2. In a device of the character described, a sawtooth wave generator, a cathode-ray tube, means to vary the output voltage of said generator, means to obtain impulses from said generator to control the beam of said cathode-ray tube, a spring contactor operated by said output voltage to make and break contact between said generator and said contactor, and means to operate said contactor by the output of said generator.

3. In a device of the character described, a. sawtooth wave generator, a cathode-ray tube, means to vary the output voltage of said generator, means to obtain impulses from said generator to control the beam of said cathode-ray tube, a spring contactor operated by said output voltage to make and break contact between said generator and said contactor, and means to control said contactor by the output of said genera-tor.

4. In a device of the character described, a cathode-ray tube having a beam intensity control and vertical and horizontal deflecting plates, a sawtooth wave generator comprising a vacuum tube having a variable resistor in its cathode circuit, a switch in parallel with said resistor, a vacuum tube having its control grid connected to the output of said sawtooth wave generator, a, relay operated by the output of said vacuum tube and adapted to connect a source of negative potential to said beam intensity control electrode of said cathode-ray tube.

5. The device of claim 4 in which at least one of said deflecting plates is coated with a high resistance material.

6. The device of claim 4 in which one pair of said deflection plates is coated with high resistance material and the plates of this pair are connected. in series.

THOMAS T. GOLDSMITH, JR. ESTLE RAY MANN.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,062,538 Van Den Bosch Dec. 1, 1936 2,098,384 Goodrich Nov. 9, 1937 2,179,097 Law Nov. 7, 1939 2,313,018 Krause Mar. 2, 1943 2,406,858 Shepherd et a1. Sept. 3, 1946 2,413,785 Robinette Jan. 7, 1947 2,425,330 Kenyon Aug. 12, 1947 

